Gangly Notes

The repetitive nature of our footsteps is the most fundamental regularity found in our gait, explaining the fundamental status of the beat in music. But we humans make a greater racket than we are typically consciously aware of. Much of our body weight consists of four heavy, gangly parts–our limbs–and when we are on the move, these ganglies are rattling about, bumping into all sorts of things. When our feet swing forward in a stride, they float barely above the ground, and very often shuffle on their way to landing. In natural terrain, the grass, rocks, dirt, and leaves can get smacked or brushed in between the beat. Sometimes one’s own body hits itself–legs hitting each other as they pass, or arms hitting the body as they swing. And often we are carrying things, like a quiver of arrows, a spear, a keychain, or a sack of wet scalps of the neighboring villagers, and these will clatter and splat about as we move.

Not only do our clattering ganglies clang in between our footsteps, they make their sounds in a time‑locked fashion to the footsteps. This is because when we take a step, we initiate a “launch” of our limbs (and any other objects carried on our bodies) into a behavior‑specific “orbit,” an orbit that will be repeated on the next step if the same behavior is repeated. In some cases the footstep causes the gangly hit outright, as when our step launches our backpack a bit into the air and it then thuds onto our back. But in other cases the step doesn’t directly cause the between‑the‑beat gangly hit so much as it triggers a sequence of motor events, such as our arms brushing against our body, which will recur at the same time delay after the next step. Exactly what the time delay will be after the step depends on the specific manner in which any given gangly part (appendage, carried object, or carried appendage) swings and bounces, which in turn depends on its physical dimensions, how it hangs, where on the body it lies, and how it participates in the behavior.

From the auditory pattern of these footstep‑time‑locked clattering ganglies, we are able to discern what people are doing. Walking, jogging, and running sound different in their patterns of hits. A sharp turn sounds different from a mover going straight. Jumping leads to a different pattern, as does skipping or trotting. Going up the stairs sounds distinct from going down. Sidestepping and backing up sound different than forward movement. Happy, angry, and sad gaits sound different. Even the special case we discussed in the previous chapter–sex–has its own banging ganglies. Close your eyes while watching a basketball game on television, and you’ll easily be able to distinguish times when the players are crossing the court from times when they are clustered on one team’s side; and you will often be able to make a good guess as to what kind of behavior, more specifically, is being displayed at any time. You can distinguish between the pattern of hits made by a locomoting dog versus cat, cow versus horse. And you can tell via audition whether your dog is walking, pawing, or merely scratching himself. It should come as no surprise that you have fine‑grained discrimination capabilities for sensing with your ears the varieties of movements we humans make, movements we hear in the pattern of gangly bangings.

If the pattern of our clanging limbs is the cue our auditory system uses to discern a person’s type of behavior, then music that has culturally evolved to sound like human movement should have gangly‑banging‑like sounds in it. And just as gangly bangings are time‑locked to the steps, music’s analog of these should be time‑locked to the beat. And, furthermore, musical banging ganglies should be crucial to the identity of a song, just as the pattern of a mover’s banging ganglies is crucial to identifying the type of behavior.

Where are these banging ganglies in music? Right in front of our ears! Musical banging ganglies are simply notes . The notes on the beat sound like footsteps (and are typically given greater emphasis, just as footsteps are more energetic than between‑the‑steps body hits), and the notes occurring between the beats are like the other body hits characterizing a mover’s behavior. Beats are footsteps, and rhythm (more generally) is the pattern of a mover’s banging ganglies. Just as between‑the‑steps body‑hit sounds are time‑locked to footsteps, notes are time‑locked to the beat. And, also like our gait, pieces of music that have the same sequence of pitches but differ considerably in rhythm are perceived to be different tunes. If we randomly change the note durations found in “Twinkle, Twinkle Little Star,” thereby obliterating the original rhythm, it will no longer be “Twinkle, Twinkle Little Star.” Similarly, if we randomly change the timing of the pattern of banging ganglies for a basketball player going up for a layup, it will no longer be the sound of a layup.

Rhythm and beat have, then, some similarities to the structure of our banging ganglies. We will discuss more similarities in the upcoming sections and in the Encore chapter. But there is one important similarity that might appear to be missing: musical notes usually come with a pitch , and yet our footsteps and gangly hits are not particularly pitchy. How can the dull thuds of our bodies possibly be pitchy enough to explain the central role of pitch in music?

If you have already read the earlier chapter on speech, then you may have begun to have an appreciation for the rings occurring when any solid‑object physical event occurs. As we discussed, we are typically not consciously aware of the rings, but our auditory system hears them and utilizes them to determine the identity of the objects involved in events (e.g., to tell the difference between a pencil and a paper clip hitting a desk). Although the pitch of a typical solid object may not be particularly salient, it can become much more salient when contrasted with the distinct pitches of other objects’ rings. For example, a single drum in a set of drums doesn’t sound pitchy, but when played in combination with larger and smaller drumheads, each drum’s pitch becomes easy to hear. The same is true for percussionists who use everyday objects for their drums–in such performances one is always surprised to hear the wide range of pitches occurring among all the usually pitchless‑seeming everyday objects. Our footsteps and banging ganglies do have pitches, consistent with the hypothesis that they are the fundamental source of musical notes. (As we will see, these gangly pitches are analogous to chords, not to melody–which, I will argue later, is driven by the Doppler effect.)

If I am right that musical notes have their origin in the sounds that humans make when moving, then notes should come in human‑gait‑like patterns . In the next section, we’ll take up a simple question in this regard: does the number of notes found between the beats of music match the number of gangly bangs between footsteps?